Method of knitting a pile fabric on a warp knitting machine

ABSTRACT

A pile fabric is produced on a Raschel knitting machine having one needle bed and three guide bars and swinging the guide bars back and forth twice during the knitting of each course by knitting a ground fabric from the threads of two guide bars and by clamping two portions of each pile thread of the third bar to each knitting needle by means of respective threads from the two guide bars guiding the threads for the ground fabric. Pile loops are formed from the pile thread portion between the clamping and the knock over edge of the trick plate. Different types of ground fabric may be used, and the pile threads may be secured to the ground fabric with or without the use of a fall plate.

United States Patent 1 1 Wilkens 1451 Jan. 16,1973

[54] METHOD OF KNITTING A PILE FABRIC ON A WARP KNITTING MACHINE [76] Inventor: Christian Wilkens, Beethovenstrasse [30] Foreign Application Priority Data Jan. 29, 1970 Germany ..P 20 03 928.5

52 us. C1 ..66/l92 [51] Int. Cl. ..D04b 23/08 [58] Field of Search ..66/] 90-195 [56] References Cited UNITED STATES PATENTS 2,435,897 2/1948 Newman ..66/194 x 3,213,646 10/1965 Van Patten ..66/l9l FOREIGN PATENTS OR APPLICATIONS 61,836 5/1968 Germany ..66/l94- 1,512,385 1/1968 France ..66/l95 OTHER PUBLICATIONS Publication, New Methods For Warp Knit Pile and Plush Fabrics, The Hosiery Trade Journal, Vol. 73, No. 873, Sept. 1966, pp. 100 to 102.

Primary ExaminerRonald Feldbaum Att0rneyl(urt Kelman [57] ABSTRACT A pile fabric is produced on a Raschel knitting machine having one needle bed and three guide bars and swinging the guide bars back and forth twice during the knitting of each course by knitting a ground fabric from the threads of two guide bars and by clamping two portions of each pile thread of the third bar to each knitting needle by means of respective threads from the two guide bars guiding the threads for the ground fabric. Pile loops are formed from the pile thread portion between the clamping and the knock over edge of the trick plate. Different types of ground fabric may be used, and the pile threads may be secured to the ground fabric with or without the use of a fall plate.

8 Claims, 6 Drawing Figures PATENTEDJANIS I975 3,710,598

IN VEN TOR cums'rlnn wune IIY mm W

AGENT METHOD OF KNITTING A PILE FABRIC ON A WARP KNITTING MACHINE This invention relates to warp knitting, and particularly to a method of producing a pile fabric on a warp knitting machine.

A fabric having pile loops was usually prepared heretofore on a warp knitting machine having two needle' beds of which one was set with plush points. The length of the pile loops in this type of machine depends on the spacing of the two trick plates. If relatively long pile loops are to be produced, the trick plates respectively associated with the needle bar and the point bar must be separated widely, and the necessary wide swing of the guide bars necessitates a reduction in the maximum knitting speed of which the machine would otherwise be capable.

It has also been proposed heretofore to lay the pile threads over knitting needles which do not participate in the knitting of the ground fabric, and to clear the pile threads. This method is limited in the thickness of the pile threads that may be employed and in the length of the pile loops. It is also not possible to use all types of ground weaves in the pile fabrics so produced.

A primary object of the invention is the provision of a knitting method for pile fabric which is capable of being performed on a relatively simple, conventional warp knitting machine.

Another object is the provision of a method which is not limited in the fineness of the pile threads employed nor in the length of the pile loops that may be formed.

A further object is the provision of a method of making a pile fabric which may be provided with any type of weave in the ground fabric.

With these and other objects in view, as will hereinafter become apparent, the invention provides a knitting method applicable to warp knitting machine having at least one needle bed and three threaded guide bars and equipped with a guide bar mechanism swing ing the guide bars back and forth twice during the knitting of each course. The threads guided by a first and second guide bar are jointly knitted into a ground fabric. Each pile thread guided by the third guide bar is clamped during theknitting of the ground fabric at two points to the same knitting needle by the threads respectively guided by the first and second guide bars. The threads of the third guide bar are thereby formed into pile loops in the knitted fabric.

Other features and many of the attendant advantages of this invention will readily be appreciated as the same becomes better understoodby reference to the following description of preferred embodiments when considered in connection with the appended drawing in which:

FIG. I is a point paper diagram of guide bar movements in a first embodiment of the knitting method of the invention;

FIG. 2 illustrates the disposition of the several threads on a knitting needle during the knitting method diagrammatically illustrated in FIG. 1, the needle being shown in a perspective view;

FIGS. 3 and 5 are'diagrams analogous to FIG. 1 and relating to respective other embodiments of the invention; and

FIGS. 4 and 6 illustrate the disposition of threads on knitting needles in the procedures of FIGS. 3 and 5 respectively in views corresponding to that of FIG. 2.

Referring now to the drawing in detail, and initially to FIG. 1, there are shown the movements of the three fully threaded guide bars L,, L and L, of a Raschel knitting machine equipped with a fall plate and a guide bar mechanism which swings the guide bars back and forth through the knitting needles twice during the knitting of each course.

The guide bar movements are produced by a non-illustrated pattern chain constructed as follows:

Front guide bar L,: 2-2,2-0/00,02

Middle guide bar L 02,2-2/64,44

Back guide bar L 2-2,00/00,2-2

The front bar L, makes straight pillar stitches, the middle guide bar L lays in threads with overlaps which are depressed to the needle shafts by the fall plate, and the back guide bar carries the pile threads which are laid in.

The knitting needles rise from the knocking-over position to their highest position. During their first swinging motion, the guide bars move backward, and the guide bar L makes an overlap. The guide bars thereafter return to the front of the machine, and the fall plate is operated. It descends and depresses the overlap threads of the guide bar L from the needle latches to the needle shafts. The fall plate thereafter is raised while the pile guide bar L makes an underlap.

During the subsequent second swinging motion of the guide bars, the latter move toward the back of the machine. The guide bar L, makes an overlap, and the guide bars make their second forward swing. As the knitting needles start descending, two spaced portions of the pile threads of the yarn guide L, are clamped to the needle shaft, as is better seen in F IG. 2.

At the clamping point 1, the laid-in thread of the ground fabric is located in front of the pile thread from the guide bar L At the clamping point 2, higher on the needle shank, the pillar thread from the front bar L, is located in front of the pile thread. When the needle bar is lowered, pile loops are formed from the portions of the pile threads between the clamping points and the non-illustrated knocking over edge of the trick plate. The needle latches are closed, and the guide bar L makes an underlap. The stitches thereafter are knocked over.

In the knitting method illustrated in FIGS. 3 and 4, the pattern chain is constructed as follows:

Front guide bar L,: 02,00/2-0,22

Middle guide bar L 22,20/00,0-2

Back guide bar L 6*6,66/00,00 The knitting machine employed does not require a fall plate. The pile threads are guided by the guide bar L,, pillar stitches are formed by the threads in guide bar L and the threads from guide bar L,-, are laid in.

As in the first-described embodiment of the invention, the needle bar ascends at the beginning of the knitting cycle from the knocking over position to its highest position, the guide bars swing backward in their first swinging motion, and the guide bar L, makes an overlap whereupon the guide bars swing forward, and an underlap of the guide L, is made in a direction opposite to the preceding overlap. The guide bars then make their second backward swing, and the guidebar L makes an overlap, whereafter the guide bars return to the front of the machine.

As the needle bar starts descending, two spaced portions of each pile thread are clamped to the same knitting needle. As is shown in FIG. 4, the laid-in thread from guide bar L is located over the pile thread from guide bar I, at clamping point 1, and the pillar thread from guide bar L is similarly located above the pile thread at clamping point 2. Pile loops are formed during the descent of the needle bar, the latches are closed, and the guide bars L and L make underlaps which are followed by knocking over of the stitches.

In the third embodiment illustrated in FIGS. and 6, the guide bar movements shown in FIG. 5 are produced by a pattern chain constructed as follows:

Front guide bar L 2-2,2-0/0-0,02

Middle guide bar L 0-2,00/2-0,2-2

Back guide bar L 0-0,00/88,8-8

The Raschel knitting machine employed is the same as in knitting the fabric described with reference to FIGS. 1 and 2.

The first or front guide bar L makes pillar stitches, the middle guide bar supplies the pile threads which form overlaps that are depressed to the needle shaft by the fall plate, and the back guide bar L supplies laid-in threads.

Starting from the knocking over position of the needle bar, the latter rises to its highest position. The guide bars make their first backward swing, and the guide bar L makes an overlap. The guide bars then swing forward, and the fall plate is operated to depress the overlaps of thread from the guide bar L from the needle latches to the needle shafts. The fall plate ascends while the guide bar L makes an underlap opposite to the preceding overlap.

The guide bars then make their second backward swing, and the guide bar L makes an overlap. The guide bars revert to the front of the machine, and the needle bar starts descending whereby the pile threads from the guide bar L are clamped to the needle shaft in two points 1 and 2. At the clamping point I, the laid-in thread is located behind the pile thread, and at the clamping point 2, the pillar thread is located in front of the pile thread.

During continuing descent of the needle bar, the latches are closed, pile loops are formed, and the guide bars L and L make underlaps. Ultimately, the stitches are knocked over.

The three embodiments described with reference to the drawing are merely illustrative, and those skilled in the art will readily modify the specific patterns illustrated without departing from the scope or spirit of the invention.

The method disclosed makes it possible to use a simple Raschel knitting machine, having a fall plate or not so equipped, for making a wide variety of pile fabrics if it is provided with at least three guide bars and a guide bar mechanism which causes the guide bars to swing forth and back twice during the knitting of each course. The fineness of the knitted goods and the length of the pile loops may be chosen at will, and the force with which the pile threads are anchored in the ground fabric may be varied by chosing the interconnection between the pile threads and the two threads forming the ground fabric.

It is a common feature of the preferred embodiments of the invention that the first clamping point at each knitting needle is provided by a laid-in thread of the ground fabric, and the second clamping point by a thread which forms stitches in the ground fabric. The pile thread is clamped to the needle in such a manner that the portion of the pile thread between the two clamping points and the knocking over edge of the trick plate expands into a pile loop during the lowering of the needle bar in the last stage of the knitting cycle.

If so desired, the clamping points may be spaced walewise in any desired manner, being arranged either in each course or in any desired other walewise distribution. The length of the pile loops may be varied by modifying the tension in the stitch-forming and laid-in threads. The higher the tension, the tighter the clamping of the pile threads, and the longer the pile loops. The spacing of the clamping points on the needle shafts from the trick plate may also be increased to lengthen the pile loops, and this is readily achieved by increasing the vertical stroke of the needle bar in a conventional manner.

Other modifications and variations of the present invention are obviously possible in the light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

l. A method of knitting a pile fabric on a warp knitting machine having at least one needle bar and three threaded guide bars, and equipped with a guide bar mechanism swinging the guide bars back and forth twice during the knitting of each course which comprises:

a. knitting threads guided by a first guide bar and a second guide bar into a ground fabric by swinging the guide bars back and forth twice in each course; and

b. forming pile loops of threads by clamping during knitting of the ground fabric at two spaced points to the same knitting needle of each thread guided by the third guide bar, said clamping being by threads respectively guided by the first and second guide bars, the overlap of the warp thread being always opposite the following overlap of thread and the underlap of the pile thread always being in the same direction to the following overlap thread, whereby the threads of said third guide bar form pile loops in the knitted fabric.

2. A method as set forth in claim 1, wherein the threads of said first guide bar are formed into pillar stitches on said knitting needles during said knitting, and the stitches of said second guide bar are laid-in into said pillar stitches to form said ground fabric.

3. A method as set forth in claim 2, wherein the threads of said third guide bar are laid-in into said ground fabric, said first guide bar being arranged in front of said second guide bar, and said third guide bar in back of said second guide bar.

4. A method as set forth in claim 3, said knitting machine being equipped with a fall plate, said second guide bar making an overlap after the first backward swing of said guide bars, and said overlap being depressed by said fall plate to the shank of each knitting needle, the third guide bar makes an underlap after the first forward swing of said guide bars, said first guide bar makes an overlap after the second backward swing of said guide bars, and said second guide bar makes an underlap after the second forward swing of the guide bars.

5. A method as set forth in claim 2, wherein knitting threads are guided by said third guide bar, said clamp- 7 ing by thread guided by the first guide bar from behind the third guide bar, and said clamping by thread guided by the second guide bar from behind the first guide bar.

6. A method as set forth in claim 1, wherein said third guide bar makes an overlap after the first backward swing of the guide bars and an underlap in a direction opposite to the direction of said overlap after the first forward swing of the guide bars, said first guide bar makes an overlap after the second backward swing of said guide bars, and said third and second guide bars make underlaps after the second forward swing of said guide bars.

7. A method as set forth in claim 2, wherein during knitting, fall plate means descends and depresses overlap threads, and wherein knitting threads are guided by said third guide bar, said clamping by thread guided by the first guide bar received from in front of the third guide bar, and said clamping by thread guided by the second guide bar received from behind the third guide bar.

8. A method as set forth in claim 2, wherein said third guide bar makes an overlap after the first backward swing of said guide bars, said overlap is depressed to the needle shafts by said fall plate, said third guide bar makes an underlap after the first forward swing of said guide bars, said first guide bar makes an overlap after the second backward swing of said guide bars, and the second and third guide bars make underlaps after the second forward swing of the guide bars. 

1. A method of knitting a pile fabric on a warp knitting machine having at least one needle bar and three threaded guide bars, and equipped with a guide bar mechanism swinging the guide bars back and forth twice during the knitting of each course which comprises: a. knitting threads guided by a first guide bar and a second guide bar into a ground fabric by swinging the guide bars back and forth twice in each course; and b. forming pile loops of threads by clamping during knitting of the ground fabric at two spaced points to the same knitting needle of each thread guided by the third guide bar, said clamping being by threads respectively guided by the first and second guide bars, the overlap of the warp thread being always opposite the following overlap of thread and the underlap of the pile thread always being in the same direction to the following overlap thread, whereby the threads of said third guide bar form pile loops in the knitted fabric.
 2. A method as set forth in claim 1, wherein the threads of said first guide bar are formed into pillar stitches on said knitting needles during said knitting, and the stitches of said second guide bar are laid-in into said pillar stitches to form said ground fabric.
 3. A method as set forth in claim 2, wherein the threads of said third guide bar are laid-in into said ground fabric, said first guide bar being arranged in front of said second guide bar, and said third guide bar in back of said second guide bar.
 4. A method as set forth in claim 3, said knitting machine being equipped with a fall plate, said second guide bar making an overlap after the first backward swing of said guide bars, and said overlap being depressed by said fall plate to the shank of each knitting needle, the third guide bar makes an underlap after the first forward swing of said guide bars, said first guide bar makes an overlap after the second backward swing of said guide bars, and said second guide bar makes an underlap after the second forward swing of the guide bars.
 5. A method as set forth in claim 2, wherein knitting threads are guided by said third guide bar, said clamping by thread guided by the first guide bar from behind the third guide bar, and said clamping by thread guided by the second guide bar from behind the first guide bar.
 6. A method as set forth in claim 1, wherein said third guide bar makes an overlap after the first backward swing of the guide bars and an underlap in a direction opposite to the direction of said overlap after the first forward swing of the guide bars, said first guide bar makes an overlap after the second backward swing of said guide bars, and said third and second guide bars make underlaps after the second forward swing of said guide bars.
 7. A method as set forth in claim 2, wherein during knitting, fall plate means descends and depresses overlap threads, and wherein knitting threads are guided by said third guide bar, said clamping by thread guided by the first guide bar received from in front of the third guide bar, and said clamping by thread guided by the second guide bar received from behind the third guide bar.
 8. A method as set forth In claim 2, wherein said third guide bar makes an overlap after the first backward swing of said guide bars, said overlap is depressed to the needle shafts by said fall plate, said third guide bar makes an underlap after the first forward swing of said guide bars, said first guide bar makes an overlap after the second backward swing of said guide bars, and the second and third guide bars make underlaps after the second forward swing of the guide bars. 